Whats a signal 0. An exhaustive search on signals landed me nowhere.
Is it possible to do something like this trap "echo $var" 0.
If so what signal does this trap catch ?
Signal 0 is a pseudo-signal, understood by ksh and compatibles, which means EOF. This "signal" gets triggered whenever the script finishes it's execution, no matter how. It's very nice to have if you want to clean up after your script (eg. temporary files), and don't want to write the code multiple times. Pretty similar to the POSIX atexit(3) C function.
well if this is a trap to catch the end of execution of script can Ctrl+C stop this execution.?